Methods for integrating cell measurement procedures of a communication apparatus and communication apparatuses utilizing the same

ABSTRACT

A communication apparatus has at least one radio transceiver module, a first subscriber identity card and a second subscriber identity card, where the first subscriber identity card corresponds to a first public land mobile network (PLMN), and the second subscriber identity card corresponds to a second PLMN. The communication apparatus includes processor logic determining whether the first PLMN and the second PLMN are the same, and for suspending a measurement procedure and a cell reselection procedure of one of the first subscriber identity card and the second subscriber identity card to reduce battery power consumption. Processor logic further triggers an unsuspended measurement procedure to tune the radio transceiver module to a plurality of corresponding channel frequency/frequencies of the neighbor cells.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 12/416,259,filed Apr. 1, 2009, now U.S. Pat. No. 8,121,601, the entirety of whichis incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an intelligent system information (SI)management method, and more particularly to an intelligent SI managementmethod for a communication apparatus equipped with more than onesubscriber identity card to integrate cell measurement procedures forreducing power consumption.

2. Description of the Related Art

The term “wireless”, normally refers to an electrical or electronicoperation, which is accomplished without the use of a “hard wired”connection. “Wireless communication”, is the transfer of informationover a distance without the use of electrical conductors or wires. Thedistances involved may be short (a few meters for television remotecontrols) or very long (thousands or even millions of kilometers forradio communications). The best known example of wireless communicationis the cellular telephone. Cellular telephones use radio waves to enablean operator to make phone calls to another party, from many locationsworld-wide. They can be used anywhere, as long as there is a cellulartelephone site to house equipment that can transmit and receive signals,which are processed to transfer both voice and data to and from thecellular telephones.

There are various well-developed and -defined cellular communicationtechnologies. For example, the Global System for Mobile communications(GSM) is a well-defined and commonly adopted communications system,which uses time division multiple access (TDMA) technology, which is amultiplex access scheme for digital radio, to send voice, data, andsignalling data (such as a dialed telephone number) between mobilephones and cell sites. The CDMA2000 is a hybrid mobile communications2.5G/3G (generation) technology standard, that uses code divisionmultiple access (CDMA) technology. The UMTS (Universal MobileTelecommunications System) is a 3G mobile communications system, whichprovides an enhanced range of multimedia services over the 2G GSMsystem. The Wireless Fidelity (Wi-Fi) is a technology defined by the802.11b engineering standard and can be used for home networks, mobilephones, video games, to provide a high-frequency wireless local areanetwork.

With the advanced development of wireless communication technologies, itis now possible to provide multiple wireless communication servicesusing different or the same communication technologies in onecommunication apparatus. Because battery sustainability is always animportant issue for an electronic device, intelligent system information(SI) management methods for a communication apparatus equipped with morethan one subscriber identity card to reduce power consumption aredesired.

BRIEF SUMMARY OF THE INVENTION

Communication apparatuses and methods for integrating cell measurementprocedures of a communication apparatus in a communication system areprovided. An embodiment of a communication apparatus comprises at leastone radio transceiver module, a first subscriber identity cardcorresponding to a first public land mobile network (PLMN), a secondsubscriber identity card corresponding to a second PLMN and a processor.The first subscriber identity card camps on a first serving cellbelonging to the first PLMN and receives a first neighbor cell listcomprising a corresponding channel frequency of at least one neighborcell of the first serving cell via the radio transceiver module. Thesecond subscriber identity card camps on a second serving cell belongingto the second PLMN and receives a second neighbor cell list comprising acorresponding channel frequency of at least one neighbor cell of thesecond serving cell via the radio transceiver module. The processor iscoupled to the first subscriber identity card, the second subscriberidentity card and the radio transceiver module, merges the firstneighbor cell list and the second neighbor cell list to obtain a mergedneighbor cell list, tunes the radio transceiver module to thecorresponding channel frequency/frequencies of the neighbor cells in themerged neighbor cell list to respectively receive a plurality of signalsfrom the neighbor cells therein, and accordingly measures and evaluatesquality of the neighbor cells therein.

An embodiment of a method for integrating cell measurement procedures ofa communication apparatus in a communication system is performed by aprocessor and comprises: receiving a first neighbor cell list comprisinga corresponding channel frequency of at least one neighbor cell of afirst serving cell camped on by a first subscriber identity card via aradio transceiver module; receiving a second neighbor cell listcomprising a corresponding channel frequency of at least one neighborcell of a second serving cell camped on by a second subscriber identitycard via the radio transceiver module; merging the first neighbor celllist and the second neighbor cell list to obtain a merged neighbor celllist; using the radio transceiver module to receive a plurality ofsignals from the neighbor cells in the merged neighbor cell list;accordingly measuring and evaluating quality of the neighbor cellstherein.

A detailed description is given in the following embodiments withreference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

The invention can be more fully understood by reading the subsequentdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 shows a communication apparatus according to an embodiment of theinvention;

FIG. 2 shows a communication apparatus according to another embodimentof the invention;

FIG. 3 shows a communication apparatus according to another embodimentof the invention;

FIG. 4 shows an exemplary network topology according to an embodiment ofthe invention;

FIG. 5 shows a flow chart of a method for integrating cell measurementprocedures of the subscriber identity cards according to a firstembodiment of the invention;

FIG. 6 shows another flow chart of a method for integrating cellmeasurement procedures of the subscriber identity cards according to thefirst embodiment of the invention;

FIG. 7 shows a flow chart of a method for integrating cell measurementprocedures of the subscriber identity cards according to a secondembodiment of the invention;

FIG. 8 a and FIG. 8 b show another flow chart of a method forintegrating cell measurement procedures of the subscriber identity cardsaccording to the second embodiment of the invention;

FIG. 9 a and FIG. 9 b show a flow chart of a method for integrating cellmeasurement procedures of the subscriber identity cards according to athird embodiment of the invention;

FIG. 10 a and FIG. 10 b show another flow chart of a method forintegrating cell measurement procedures of the subscriber identity cardsaccording to the third embodiment of the invention; and

FIG. 11 shows a flow chart of the method for intelligently selectingdifferent cell measurement integral processes according to a fourthembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of the best-contemplated mode of carryingout the invention. This description is made for the purpose ofillustrating the general principles of the invention and should not betaken in a limiting sense. The scope of the invention is best determinedby reference to the appended claims.

FIG. 1 shows a communication apparatus according to an embodiment of theinvention. As shown in FIG. 1, communication apparatus 100A comprisessubscriber identity cards 101 and 102, a baseband module 103, and aradio transceiver module 104, wherein the baseband module 103 is coupledto the subscriber identity cards 101 and 102, and the radio transceivermodule 104. The radio transceiver module 104 receives wireless radiofrequency signals, converts the received signals to baseband signals tobe processed by the baseband module 103, or receives baseband signalsfrom the baseband module 103 and converts the received signals towireless radio frequency signals to be transmitted to a peer device. Theradio transceiver module 104 may comprise a plurality of hardwaredevices to perform radio frequency conversion. For example, the radiotransceiver module 104 may comprise a mixer to multiply the basebandsignals with a carrier oscillated in the radio frequency of the wirelesscommunication system, wherein the radio frequency may be, for example,900 MHz or 1800 MHz for a global system for mobile communication (GSM),or 1900 MHz for a Universal Mobile Telecommunications System (UMTS). Thebaseband module 103 further converts the baseband signals to a pluralityof digital signals, and processes the digital signals, and vice versa.The baseband module 103 may also comprise a plurality of hardwaredevices to perform baseband signal processing. The baseband signalprocessing may comprise analog to digital conversion (ADC)/digital toanalog conversion (DAC), gain adjustments, modulation/demodulation,encoding/decoding, and so on. The baseband module 103 further comprisesa memory device 106 and a processor 105 for controlling the operationsof the baseband module 103, the radio transceiver module 104, and thesubscriber identity cards 101 and 102 plugged into two sockets,respectively. The processor 105 reads data from the plugged insubscriber identity cards 101 and 102 and writes data to the pluggedsubscriber identity cards 101 and 102. It is to be noted that the memorydevice 106 may also be configured outside of the baseband module 103 andthe invention should not be limited thereto.

According to another embodiment of the invention, the communicationapparatus comprising more than one subscriber identity card, may alsocomprise more than one baseband module and radio transceiver module,respectively, for each subscriber identity card. FIG. 2 and FIG. 3respectively show communication apparatuses according to otherembodiments of the invention. As shown in FIG. 2 and FIG. 3,communication apparatus 100B comprises subscriber identity cards 101 and102, baseband modules 103A and 103B, and radio transceiver modules 104Aand 104B, wherein the baseband module 103A is coupled to the subscriberidentity card 101 and the radio transceiver module 104A, and thebaseband module 103B is coupled to the subscriber identity card 102 andthe radio transceiver module 104B. The operations of the basebandmodules 103A and 103B are similar with that of the baseband module 103and are not described here for brevity. Similarly, the operations of theradio transceiver module 104A and 104B are similar with that of theradio transceiver module 104 and are not described here for brevity. Itis noted that in FIG. 2, the baseband module 103A comprises a memorydevice 106A and a processor 105A for controlling the operations of thesubscriber identity card 101, the baseband module 103A and the radiotransceiver module 104A, and the baseband module 103B also comprises amemory device 106B and a processor 105B for controlling the operationsof the subscriber identity card 102, the baseband module 103B and theradio transceiver module 104B. The processors 105A and 105B may becoupled and communicate with each other. The data stored in memorydevices 106A and 106B may be shared and accessed by both of theprocessors 105A and 105B. For example, one of the processors may be amaster processor and the other one may be a slave processor to cooperatewith the master processor. As shown in FIG. 3, according to stillanother embodiment of the invention, the communication apparatus 100Cmay comprise one memory device 106C and one processor 105C forcontrolling the operations of the subscriber identity cards 101 and 102,the baseband modules 103A and 103B, and the radio transceiver modules104A and 104B. The operations of the processor 105C are similar withthat of the processor 105 and are not described here for brevity. Thedescribed processors 105, 105A, 105B and 105C may be general-purposeprocessors when executing program code perform the mentioned controloperations. The described memory 106, 106A, 106B and 106C may compriseat least one of read only memory (ROM), random access memory (RAM), NORflash and NAND flash for storing program code and data.

FIG. 4 shows an exemplary network topology according to an embodiment ofthe invention. The communication apparatus 100 shown in FIG. 4, may bethe communication apparatuses 100A, 100B and 100C previously illustratedin FIG. 1 to FIG. 3. Thus, from hereinafter, the communication apparatus100 will be used to represent all like previously described apparatusesfor brevity. The communication apparatus 100, equipped with more thanone subscriber identity card, may simultaneously access more than onenetwork 203 and 204 of the same or different communication technologies,where the network 203 or 204 may be the GSM, WCDMA, Wi-Fi, CDMA2000 orTime Division-Synchronous Code Division Multiple Access (TD-SCDMA)network, or Internet, or the like, after camping on or associating withthe cells managed by access stations 201 and 202, where the accessstation 201 or 202 may be a base station, a node-B, an access pointcompatible with 802.1a, 802.1b or 802.1g. The networks 203 and 204 maybe established by the same or different operators (or so-called publicland mobile network (PLMN)). The communication apparatus 100 may issuean apparatus originated communication request, such as a voice call, adata call, a video call, or a voice over Internet Protocol (VoIP) call,to a called party (i.e. the corresponding peer of another wired orwireless communication apparatus) through at least one of the networks203 and 204 with corresponding intermediary apparatuses 205 and 206 (forexample, the GSM network with a Mobile Switching Center (MSC), theWCDMA/TD-SCDMA network with a Radio Network Controller (RNC), or theInternet with a Session Initiation Protocol (SIP) server), or throughthe Public Switched Telephone Network (PSTN) 207 or any combinationsthereof, by using any of the equipped subscriber identity cards.Moreover, the communication apparatus 100 may receive an apparatusterminated communication request, also referred to as a mobileterminated (MT) call request, such as an incoming phone call, with anyof the subscriber identity cards from a calling party. It is to beunderstood that there may be one or more gateways positioned betweenheterogeneous types of networks.

According to an embodiment of the invention, the subscriber identitycards 101 and 102 may relate to one type of wireless communicationsystem. For example, the subscriber identity card 101 or 102 may be thesubscriber identity module (SIM) card corresponding to the GSM system,or the universal subscriber identity module (USIM) card corresponding tothe UMTS system, or the removable user identity module (RUIM) card orthe CDMA Subscriber Identity Module (CSIM) card corresponding to theCDMA2000 communication system, or others. An SIM card typically containsuser account information, an international mobile subscriber identity(IMSI) and a set of SIM application toolkit (SAT) commands and providesstorage space for phone book contacts. The processor, such as 105, 105A,105B or 105C, of the baseband module, such as 103, 103A or 103B, mayinteract with a micro control unit (MCU) of the SIM card to fetch dataor SAT commands from the plugged in SIM card. The communicationapparatus 100 is immediately programmed after being plugged into the SIMcard. The SIM card may also be programmed to display custom menus forpersonalized services. The communication apparatus 100 may be pluggedinto an USIM card for UMTS (also called 3G) telephony communication. TheUSIM card stores user account information, IMSI, authenticationinformation and a set of USIM Application Toolkit (USAT) commands andprovides storage space for text messages and phone book contacts. Thebaseband processor 105, 105A, 105B or 105C may interact with an MCU ofthe USIM card to fetch data or SAT commands from the plugged in USIMcard. The phone book on the USIM card is more enhanced than that on theSIM card. For authentication purposes, the USIM card may store along-term preshared secret key K, which is shared with theAuthentication Center (AuC) in the network. The USIM MCU may verify asequence number, that may be within a range, by using a window mechanismto avoid replay attacks, and generates the session keys CK and IK to beused in the confidentiality and integrity algorithms of the KASUMI (alsotermed A5/3) block cipher in the UMTS system. The communicationapparatus 100 is immediately programmed after being plugged into theUSIM card. The IMSI is a unique number associated with a global systemfor mobile communication (GSM) or a universal mobile telecommunicationssystem (UMTS) network user. The IMSI may be sent by the communicationapparatus 100 to the GSM or UMTS network to acquire other details of themobile user in the Home Location Register (HLR) or, as locally copied,in the Visitor Location Register (VLR). An IMSI is typically 15 digitslong, but can be shorter. The first 3 digits are the Mobile Country Code(MCC), and the following digits, are the Mobile Network Code (MNC),which are either 2 digits (European standard) or 3 digits (NorthAmerican standard). The remaining digits are the mobile subscriberidentification number (MSIN) for the GSM or UMTS network user.

When the communication apparatus 100 equipped with more than onesubscriber identity card (e.g. 101 and 102) is powered on, eachsubscriber identity card starts to search for a network and select asuitable cell to camp on. As an example, the subscriber identity card101 belonging to a corresponding public land mobile network (hereinaftercalled the PLMNA for brevity) may camp on a cell (hereinafter called theServing CellA for brevity) managed by an access station (e.g. 201 or 202as shown in FIG. 4) belonging to the PLMNA, and the subscriber identitycard 102 belonging to a corresponding public land mobile network(hereinafter called the PLMNB for brevity) may also camp on a cell(hereinafter called the Serving CellB for brevity) managed by an accessstation (e.g. 201 or 202) belonging to the PLMNB. The PLMNA and PLMNBmay be the same or different PLMN, and when the PLMNA and PLMNB are thesame PLMN, the Serving CellA and Serving CellB may be the same ordifferent. After camping on the corresponding cell, each subscriberidentity card receives a corresponding neighbor cell list (hereinaftercalled NCListA and NCListB for brevity) comprising a correspondingchannel frequency of at least one neighbor cell via the radiotransceiver module (e.g. 104, 104A or 104B). According to an embodimentof the invention, the communication apparatus 100 may intelligentlydetermine how to integrate cell measurement procedures of two or moresubscriber identity cards to save the battery power according to thePLMN and serving cells of subscriber identity cards. As an example, whenthe processor (e.g. 105, 105A, 105B or 105C) determines that the PLMNAand PLMNB are the same PLMN (as an example, according to the PLMNidentity (PLMN ID) stored in the subscriber identity cards 101 and 102),the processor may merge the NCListA and NCListB (for example, byappending the information indicating the corresponding channel frequencyof the neighbor cell(s) of the Serving CellB that does/do not exist inthe NCListA of Serving CellA therein) and combine the cell measurementprocedures of the subscriber identity cards into one measurementprocedure, so as to prevent monitoring of the same neighbor cell twice,and further save power consumption. The merging of the neighbor celllists is further described as the following example. When the NCListAcomprises information indicating the corresponding channel frequency ofneighbor cells A1 and A2, and the NCListB comprises informationindicating the corresponding channel frequency of neighbor cells A2 andA3, the processor merges the NCListA and NCListB to obtain a mergedneighbor cell list NCListC comprising information indicating thecorresponding channel frequency of the neighbor cells A1, A2 and A3.That is, the merged neighbor cell list NCListC contains only one recordfor the common neighbor cell A2 that exists in both of the NCListA andNCListB. After obtaining the merged neighbor cell list NCListC, theprocessor may suspend a measurement procedure of one of the subscriberidentity card 101 and 102 and leverage the measurement task to theunsuspended measurement procedure. Thus, the common neighbor cell of thesubscriber identity cards 101 and 102 would not be measured twice andthe measurement results stored in the memory (e.g. 106, 106A, 106B or106C) may be shared between the subscriber identity cards 101 and 102.

FIG. 5 shows a flow chart of a method for integrating cell measurementprocedures of the subscriber identity cards according to a firstembodiment of the invention. As shown in FIG. 5, the processor (e.g.105, 105A, 105B or 105C) merges the neighbor cell lists NCListA andNCListB of the subscriber identity cards 101 and 102 to obtain a mergedneighbor cell list (Step S501). Next, the processor suspends ameasurement procedure of one of the subscriber identity cards anddirects the unsuspended measurement procedure to perform the measurementtask for the merged neighbor cell list (Step S502). Next, the processortriggers the unsuspended measurement procedure to measures qualities ofthe neighbor cells in the merged neighbor cell list (Step S503).According to the embodiment of the invention, the measurement proceduremay be periodically performed. As an example, a tick may be periodicallysent by a lower layer hardware device or software module to notify theupper layer one to trigger the unsuspended measurement procedure. Whenthe measurement procedure is triggered, an oscillator in one radiotransceiver module (e.g. 104, 104A or 104B) may be tuned to thecorresponding channel frequencies of the neighbor cells in the mergedneighbor cell list to respectively receive signals from the neighborcells, in which the quality of the neighbor cells may be measuredaccording to the signal power of corresponding received signals. Themeasurement result may be stored in the memory (e.g. 106, 106A, 106B or106C) to be shared between the subscriber identity cards 101 and 102.Thus, according to the first embodiment of the invention, the commonneighbor cell(s) of the subscriber identity cards 101 and 102 may onlybe measured once during every periodic measurement procedure. Thus, thebattery power is greatly saved. Finally, the processor may evaluate thequality of the neighbor cells for the subscriber identity cards 101 and102 to further determine whether to trigger a cell reselection procedurefor the subscriber identity cards 101 and 102 respectively (step S504).

According to the first embodiment of the invention, when thecommunication apparatus 100 is equipped with two radio transceivermodules (such as 104A and 104 B shown in FIG. 3) each respectivelycorresponding to one of the subscriber identity cards 101 and 102, theradio transceiver module corresponding to the subscriber identity cardwith the suspended measurement procedure may also be turned off so as tofurther save battery power. FIG. 6 shows another flow chart of a methodfor integrating cell measurement procedures of the subscriber identitycards according to the first embodiment of the invention, with thecommunication apparatus 100 being equipped with more than one radiotransceiver module. As shown in FIG. 6, steps S601-S602 and S604-S605are respectively similar to steps S501-S502 and S503-S504, and areomitted here for brevity. In step S603, the radio transceiver modulecorresponding to the subscriber identity card with suspended measurementprocedure is turned off to further save battery power. According to theembodiment of the invention, the radio transceiver module correspondingto the suspended measurement procedure may be turned on again when it isfurther determined that a cell reselection procedure should be triggeredaccording to the evaluation results.

According to a second embodiment of the invention, when the processor(e.g. 105, 105A, 105B or 105C) determines that the PLMNA and PLMNB arethe same PLMN, and the serving cells Serving CellA and Serving CellB arealso the same, the processor may further combine the cell reselectionprocedures of the subscriber identity cards into one cell reselectionprocedure, so as to save battery power. When camping on a cell, thecommunication apparatus 100 may periodically search for a better qualitycell for each subscriber identity card according to the cell reselectioncriteria in an idle mode or a connected mode. For example, if thecommunication apparatus 100 is moved, the current camped on cell (i.e.serving cell) may become unsuitable. Hence, the communication apparatus100 may perform a cell reselection procedure to reselect a suitable cellas a next serving cell for each subscriber identity card. Thecommunication apparatus 100 may periodically measure the neighbor cells'power (e.g. as in the measurement procedure previously described) andthe obtained measurement result (e.g. in steps S504 and S605) may be areference of the cell reselection procedure. According to the secondembodiment of the invention, since the current serving cells ServingCellA and Serving CellB are also the same, the neighbor cell listsNCListA and NCListB may also be the same. Thus, the cell reselectiondecision may be made by one subscriber identity card, and the systeminformation of a candidate suitable cell may also be collected by thesubscriber identity card and shared to the other subscriber identitycard.

FIG. 7 shows a flow chart of a method for integrating cell measurementprocedures of the subscriber identity cards according to a secondembodiment of the invention. As shown in FIG. 7, the processor (e.g.105, 105A, 105B or 105C) suspends a measurement procedure of one of thesubscriber identity cards and direct the unsuspended measurementprocedure to perform the measurement task for the merged neighbor celllist (Step S701). Next, the processor also suspends a cell reselectionprocedure of the subscriber identity card with a suspended measurementprocedure (Step S702). Next, the processor triggers the unsuspendedmeasurement procedure to measures quality of the neighbor cell(s) in theneighbor cell list (Step S703). As previously described, the measurementresult may be stored in the memory (e.g. 106, 106A, 106B or 106C) to beshared between the subscriber identity cards 101 and 102. Next, theprocessor evaluates the quality of the neighbor cell(s) according to themeasurement result (Step S704). When at least one neighbor cell withsignal quality better than the current serving cell, the processor mayobtain a preferred neighbor cell list comprising the detected neighborcell (s) (also called preferred neighbor cell(s)). Next, the processordetermines whether to trigger the cell reselection procedure (StepS705). As previously described, according to some predeterminedreselection criteria, when the current serving cell is determined to benot suitable anymore and there is one or more neighbor cells that is/arecapable of providing stronger signal power than the current servingcell, a cell reselection procedure may be triggered. When there is noneed to trigger the cell reselection procedure, the procedure may goback to step S703 to perform the next run of quality measurement for theneighbor cell(s).

On the other hand, when the processor determines to trigger the cellreselection procedure, the processor further determines whether there ismore than one preferred neighbor cell in the preferred neighbor celllist (Step S706). When there is only one preferred neighbor cell, theprocessor further triggers the subscriber identity card with theunsuspended measurement procedure to receive corresponding systeminformation from the preferred neighbor cell (Step S707). When there ismore than one preferred neighbor cell, the processor further triggersboth of the subscriber identity cards 101 and 102 to respectivelyreceive corresponding system information from the two preferred neighborcells with top two best quality in the preferred neighbor cell list inparallel (Step S708). Finally, the received system information of thepreferred neighbor cell(s) are stored in the memory so as to be sharedbetween the subscriber identity cards 101 and 102 (Step S709), and thesubscriber identity cards 101 and 102 may further decide whether toreselect (camp on) the preferred neighbor cell according to the receivedsystem information. According to an embodiment of the invention, onesubscriber identity card (or the corresponding processor) may decidewhether a preferred neighbor cell is suitable to be the next servingcell according to the received system information and determine whetherto reselect the decided cell, and the other subscriber identity card mayfollow the same decision to reselect the decided cell. According toanother embodiment of the invention, subscriber identity cards 101 and102 (or the corresponding processor(s)) may respectively determine asuitable neighbor cell and determine whether to reselect the determinedcell.

According to the second embodiment of the invention, when thecommunication apparatus 100 is equipped with two radio transceivermodules (such as 104A and 104 B shown in FIG. 3) each respectivelycorresponding to one of the subscriber identity cards 101 and 102, thecorresponding radio transceiver module corresponding to the subscriberidentity card with the suspended measurement procedure may also beturned off so as to further save battery power as previously described.FIG. 8 a and FIG. 8 b show another flow chart of a method forintegrating cell measurement procedures of the subscriber identity cardsaccording to the second embodiment of the invention, with thecommunication apparatus 100 being equipped with more than one radiotransceiver module. As shown in FIG. 8 a and FIG. 8 b, steps S801-S802are respectively similar to steps S701-S702, steps S804-S808 arerespectively similar to steps S703-S707, and steps S810 and S812 arerespectively similar to steps S708 and S709, and are omitted here forbrevity. In step S803, the radio transceiver module corresponding to thesubscriber identity card with the suspended measurement procedure isturned off to further save battery power. In step S809, the radiotransceiver module corresponding to the subscriber identity card withthe suspended measurement procedure is turned on so that thecommunication apparatus may receive corresponding system informationfrom two preferred neighbor cells simultaneously via two radiotransceiver modules, and the radio transceiver module is turned offagain in Step S811 after receiving the corresponding system informationto further save battery power.

According to a third embodiment of the invention, when the processor(e.g. 105, 105A, 105B or 105C) determines that the PLMNA and PLMNB arenot the same PLMN, the processor may also integrate the cell measurementtask under some circumstances. According to the third embodiment of theinvention, when the communication apparatus 100 is moved to an areawithout radio coverage of one PLMN (for example, PLMNA), the neighborcell list of the subscriber identity card 101 may also be merged to thatof the subscriber identity card 102 so as to regain service withreference to power measuring of the latest neighbor cells via thesubscriber identity card 102, instead of blindly performing a full bandscan. FIG. 9 a and FIG. 9 b show a flow chart of a method forintegrating cell measurement procedures of the subscriber identity cardsaccording to a third embodiment of the invention. The process beginswhen a cell measurement and reselection procedure of either onesubscriber identity card is performed (Step S901). According to the cellreselection results, the processor determines whether the subscriberidentity card (e.g. 101) is out of radio coverage (or so-called out ofservice) of its corresponding PLMN (e.g. PLMNA) (Step S902). As anexample, when the serving cell is not suitable anymore, and there isalso no other qualified neighbor cells, the subscriber identity card maybe determined out of radio coverage of its corresponding PLMN. When thesubscriber identity card is not out of service, the process goes back tothe periodic cell measurement and reselection procedures in step S901.On the other hand, when the subscriber identity card is out of service,the processor further determines whether another subscriber identitycard (e.g. 102) is still in radio coverage of its corresponding PLMN(e.g. PLMNB) (Step S903). When the subscriber identity card 102 is stillin service, the processor further determines whether the communicationapparatus 100 has now slowly moved according to a mobility status (StepS904). The processor may continuously monitor a total number of cellreselections nCR for the subscriber identity card for a past time periodTcrmax and accordingly obtain the mobility status thereof. For example,the processor obtains a fast-moving status when detecting seven or morecell reselections for a past time period (e.g. one ranging from 2 to 4seconds), a normal-moving status when detecting that a total number ofcell reselections is less than seven and greater than five for the pasttime period, and a slow-moving status when detecting five or less cellreselections for the past time period. It is noted that the processormay determine whether the communication apparatus 100 has moved slowlyor quickly according to other criteria and the invention should not belimited thereto. When the communication apparatus 100 is moved slowly,the processor incrementally appends the latest neighbor cell listsNCListA of the subscriber identity card 101 into the NCListB of thesubscriber identity card 102 (Step S905). Next, the processorperiodically triggers a measurement procedure (as previously described)of the subscriber identity card 102 to receive the signals from theneighbor cells in the merged neighbor cell list so that the neighborcells for the out-of-service subscriber identity card 101 are stillmonitored and measured by the subscriber identity card 102 for futureservice regain (Step S906). For example, when the communicationapparatus 100 is currently moved into an elevator, the subscriberidentity card may be temporarily out of service. Since the communicationapparatus 100 is slowly moved in the horizontal direction, the neighborcells may remain unchanged. Thus, a normal service regain according tothe latest neighbor cell list may be performed instead of a full bandscan so as to reduce search time and power consumption. Next, theprocessor determines whether the out-of-service subscriber identity card101 has regained service according to the measurement result (StepS907). As an example, the processor evaluates the quality of theneighbor cell of the out-of-service subscriber identity card 101according to the measurement result to obtain a qualified cell, andtriggers a service regain procedure for the subscriber identity card 101to camp on the qualified cell. When the subscriber identity card 101regains service, the appended neighbor cells for the subscriber identitycard 101 is cleared from the NCListB (Step S908). On the other hand,when the subscriber identity card 101 has not regained service, theprocedure goes back to step S906 to keep monitoring the neighbor cellsfor the out-of-service subscriber identity card 101.

When the communication apparatus 100 is not moved slowly or when theother subscriber identity card (e.g. 102) is also out of the radiocoverage of its corresponding PLMN, the processor triggers a full bandscan procedure of the subscriber identity card 101 (Step S909) so as tofacilitate the subscriber identity card 101 to regain service. As anexample, during the full band scan procedure, the processor may find outat least one cell for the subscriber identity card 101, trigger ameasurement procedure of the subscriber identity card 101 to receive thesignals from one of the found cells, evaluate the quality of the cellfor the subscriber identity card 101 according to the measurement resultto obtain a qualified cell, and trigger a service regain procedure forthe subscriber identity card 101 to attempt to camp on the qualifiedcell. Next, the processor determines whether the out-of-servicesubscriber identity card 101 has regained service according to themeasurement result (Step S910). When the subscriber identity card 101regains service, the procedure goes back to step S901. On the otherhand, when the subscriber identity card 101 does not regain service, theprocedure goes back to step S909 to locate another qualified cell.

According to the third embodiment of the invention, when thecommunication apparatus 100 is equipped with two radio transceivermodules (such as 104A and 104 B shown in FIG. 3) each respectivelycorresponding to one of the subscriber identity cards 101 and 102, thecorresponding radio transceiver module of the out-of-service subscriberidentity card may also be turned off so as to further save battery poweras previously described. FIG. 10 a and FIG. 10 b show another flow chartof a method for integrating cell measurement procedures of thesubscriber identity cards according to the third embodiment of theinvention, with the communication apparatus 100 being equipped with morethan one radio transceiver module. As shown in FIG. 10 a and FIG. 10 b,steps S1001-S1005 are respectively similar to steps S901-S905, stepsS1007-S1009 are respectively similar to steps S906-S908, and stepsS1011-S1012 are respectively similar to steps S909-S910, and are omittedhere for brevity. In step S1006, the radio transceiver modulecorresponding to the out-of-service subscriber identity card (e.g. 101)is turned off to further save battery power. In step S1010, the radiotransceiver module corresponding to the out-of-service subscriberidentity card is turned on again when the service is regained.

FIG. 11 shows a flow chart of the method for intelligently selecting onecell measurement integration process mentioned above according to afourth embodiment of the invention. As previously described, when thecommunication apparatus 100 is powered on and a network search isperformed (Step S1101), each subscriber identity card selects and campon a suitable cell (Step S1102). Next, the processor determines whetherthe corresponding PLMNs (for example, PLMNA and PLMNB) of the insertedsubscriber identity cards are the same (Step S1103). When the PLMNs arenot the same, the processor integrates the cell measurement proceduresof the subscriber identity cards according to the corresponding radiocoverage (Step S1107). For related integration methods, reference may bemade to the third embodiment as shown in FIG. 9 a and FIG. 9 b and FIG.10 a and FIG. 10 b and the corresponding description previouslyintroduced. When the PLMNs are the same, the processor furtherdetermines whether the corresponding serving cells of the insertedsubscriber identity cards are the same (Step S1104). When thecorresponding serving cells of the inserted subscriber identity cardsare the same, the processor integrates the cell measurement proceduresand cell reselection procedures of the subscriber identity cards (StepS1105). For related integration methods, reference may be made to thesecond embodiment as shown in FIG. 7, FIG. 8 a and FIG. 8 b and thecorresponding description previously introduced. When the correspondingserving cells of the inserted subscriber identity cards are not thesame, the processor integrates the cell measurement procedures of thesubscriber identity cards (Step S1106). For related integration methods,reference may be made to the first embodiment as shown in FIG. 5 andFIG. 6 and the corresponding description previously introduced. For theintelligent integration mechanism of the invention, duplicatedmeasurement and cell reselection tasks or unnecessary full band scansmay be prevented, thus greatly conserving battery power.

While the invention has been described by way of example and in terms ofpreferred embodiment, it is to be understood that the invention is notlimited thereto. Those who are skilled in this technology can still makevarious alterations and modifications without departing from the scopeand spirit of this invention. Therefore, the scope of the presentinvention shall be defined and protected by the following claims andtheir equivalents.

1. A communication apparatus having at least one radio transceivermodule, a first subscriber identity card and a second subscriberidentity card, where the first subscriber identity card corresponds to afirst public land mobile network (PLMN), and the second subscriberidentity card corresponds to a second PLMN, the communication apparatuscomprising: processor logic determining whether the first PLMN and thesecond PLMN are the same; processor logic, when the first and the secondPLMNs are the same, suspending a measurement procedure and a cellreselection procedure of one of the first subscriber identity card andthe second subscriber identity card to reduce battery power consumption;processor logic triggering an unsuspended measurement procedure to tunethe radio transceiver module to a plurality of corresponding channelfrequency/frequencies of the neighbor cells to respectively receive aplurality of signals from the neighbor cells therein, and accordinglymeasuring and evaluating quality of the neighbor cells therein; andprocessor logic triggering an unsuspended cell reselection procedure todetermine whether to reselect one neighbor cell with better quality thanthat of the corresponding serving cell according to measurement andevaluation results.
 2. The communication apparatus as claimed in claim1, further comprising processor logic receiving system information fromthe neighbor cell with better quality than that of the correspondingserving cell via the radio transceiver module, and shares the receivedsystem information to the suspended cell reselection procedure.
 3. Thecommunication apparatus as claimed in claim 2, further comprisingprocessor logic camping on the neighbor cell with better quality thanthat of the corresponding serving cell for both the first and secondsubscriber identity cards.
 4. The communication apparatus as claimed inclaim 1, wherein at least one of the first subscriber identity card andthe second subscriber identity card is the subscriber identity module(SIM) card corresponding to the global system for mobile communications(GSM), the universal subscriber identity module (USIM) cardcorresponding to the universal mobile telecommunications system (UMTS)or time division-synchronous code division multiple access (TD-SCDMA)network, or the removable user identity module (RUIM) card or the CDMAsubscriber identity module (CSIM) card corresponding to the codedivision multiple access (CDMA) 2000 communication system.
 5. Thecommunication apparatus as claimed in claim 1, wherein the communicationapparatus accompanies with two radio transceiver modules respectivelycorresponding to the first and the second subscriber identity cards,further comprising: processor logic turning off the radio transceivermodule corresponding to the subscriber identity card with the suspendedmeasurement procedure.
 6. A method for integrating cell measurementprocedures of a communication apparatus, wherein the communicationapparatus comprises at least one radio transceiver module, a firstsubscriber identity card belonging to a first public land mobile network(PLMN), a second subscriber identity card belonging to a second PLMN,and a processor, the method being performed by the processor andcomprising: receiving determining whether the first PLMN and the secondPLMN are the same; when the first and the second PLMNs are the same,suspending a measurement procedure and a cell reselection procedure ofone of the first subscriber identity card and the second subscriberidentity card to reduce battery power consumption; triggering anunsuspended measurement procedure to tune to a plurality ofcorresponding channel frequency/frequencies of the neighbor cells torespectively receive a plurality of signals from the neighbor cellstherein, and accordingly measuring and evaluating quality of theneighbor cells therein; triggering an unsuspended cell reselectionprocedure to determine whether to reselect one neighbor cell with betterquality than that of the corresponding serving cell according tomeasurement and evaluation results.
 7. The method as claimed in claim 6,further comprising receiving system information from the neighbor cellwith better quality than that of the corresponding serving cell, andshares the received system information to the suspended cell reselectionprocedure.
 8. The method as claimed in claim 7, further comprisingcamping on the neighbor cell with better quality than that of thecorresponding serving cell for both the first and second subscriberidentity cards.
 9. The method as claimed in claim 6, at least one of thefirst subscriber identity card and the second subscriber identity cardis the subscriber identity module (SIM) card corresponding to the globalsystem for mobile communications (GSM), the universal subscriberidentity module (USIM) card corresponding to the universal mobiletelecommunications system (UMTS) or time division-synchronous codedivision multiple access (TD-SCDMA) network, or the removable useridentity module (RUIM) card or the CDMA subscriber identity module(CSIM) card corresponding to the code division multiple access (CDMA)2000 communication system.